WASHINGTON: Tech billionaire Elon Musk joked on Wednesday about Republicans' defeat in US midterm elections after spending hundreds of millions of dollars to help the party.

Democrats seized control of the US Congress on Tuesday, capturing both the Senate and House of Representatives in a stunning rejection of President Donald Trump's political agenda.

"Guess my election-interfering space lasers didn't work this time," Musk said on X, including the shrug emoji.

Musk contributed nearly half a billion dollars to Republican political efforts, making him the largest individual contributor in a federal election cycle since unlimited election spending was allowed in 2010, according to campaign finance tracker OpenSecrets.